


To Play With Fire

by orphan_account



Series: Sansby Oneshots (Smut) [2]
Category: Undertale (Video Game)
Genre: Blindfolds, Dom/sub, Ecto-Vagina (Undertale), Fluff, I mean Grillby smacked a bitch todayso-, Jaide_MCYT, Kinda?, Light Bondage, M/M, Mating Cycles/In Heat, Possessive Behavior, Pregnancy Scare, Rough Sex, Scratching, Sensory Deprivation, Sub Sans, Tra la la~ Beware the woman who is bad at tagging, dom grillby, good enough idk, here we go-, me trying to remember what kinks i put in-
Language: English
Status: Completed
Published: 2020-07-07
Updated: 2020-07-07
Packaged: 2021-03-04 22:00:45
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,828
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25123558
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: They just wanna go on a date without Sans getting harrassed man- So at first its superrrr fluffy foreplay, then Sans says a Lil sum not knowing what it meant, and a bitch got wrecked- At the end, PREGANANANANANANT----
Relationships: Grillby/Sans (Undertale), Sansby
Series: Sansby Oneshots (Smut) [2]
Series URL: https://archiveofourown.org/series/1818274
Comments: 1
Kudos: 66





	To Play With Fire

Grillby and Sans were innocently walking home after a very enjoyable date, happily talking about their favorite scenes in the movie they watched. “remember the horse dick joke-” Grillby chuckled, of course of all the lines in the movie Sans liked that one. “I liked the meaning behind the grandparents wanting to stay back, ‘I’ve been alive for many years, but I’ve only just learned how to fly.’ It has a lot of meaning, you know?” Sans’ expression shifted into something soft and caring, a face Grillby wore often.

“fox, I love you-”

Grillby, caught off guard, blushed heavily. “Ah, Sans!” The skeleton in question grinned, grasping the taller’s hand and squeezing it, not letting it go after. The fire monster squeezed back, smiling adoringly at the smaller before leaning down and placing a soft kiss on his nose. The loving couple made eye contact, then blushed and looked away.

They walked further down the street hand-in-hand until passing an alleyway in which a was with jet black, messy hair stumbled out of. Purely by instinct, Grillby immediately pulled Sans away from the man and into his chest. The man and the smaller monster caught eye contact, “Ooh~ W-What do I have he-here??” The man slurred heavily, drunk out of his mind. He completely ignored Grillby, reaching out for Sans. The fire monster quickly took a step back, bringing Sans with him.

The man followed, reaching out sluggishly, yet quicker than Grillby could move Sans away, and the man grabbed onto his target. He latched onto Sans’ arm, tugging down his shirt until he could see the smaller’s collar bone. Sans froze, the hand sliding up and onto his shoulder as he started to panic. Grillby shot his left arm out in front of Sans, pushing him back with ease, before punching the man square in the temple. He dropped, knocked out from the force of the punch.

Grillby quickly picked Sans up, something the smaller usually would blush hard at and tell the taller to put him down, but instead just latched onto him. Grillby turned the corner to see the soft glow of his restaurant getting closed up by one of his workers. He walked in, but the employee had already left. He turned off the light then walked upstairs, once he got to the bedroom, “...Sans? ...Love…? Are...Are you okay?” The smaller nodded shallowly, trembling, he looked up to meet Grillby’s eyes, “wreck me.”

Grillby did a double-take, “Wh-What?” The smaller repeated himself, “wreck me. I don’t want you to think i-i’m un-unloyal because i-i didn’t m-move…” Grillby hushed him, “Sans, Love, you were scared… I know you didn’t like what he was doing. You don’t need to feel like you have to prove anything to me…” Sans looked down, seeing dirt on his sleeve where the man grabbed him. He then realized the man touched his shoulder and cringing at the black he found there.

Grillby, again, picked him up with ease, carrying him to the bathroom before grabbing a small hand towel. He soaked it with warm water before rubbing it gently across his lover’s shoulder, easily wiping the grime away. He slipped off his lover’s dirty shirt before hugging him close. “I love you, Sans. If anyone tells you otherwise, they are wrong because you are incredibly precious to me.” Sans blushed, smiling softly, “d-don’t talk like that…”

Grillby kissed him gently, dropping the towel in the hamper and cupping his hands under Sans’ thighs, using the leverage to both deepen the kiss and pick him up. The smaller hummed, allowing Grillby to explore his mouth. Their tongues danced while the taller carefully slid his hand up and down the smaller’s spine. Sans’s whimper was muffled by the kiss, but neither minded.

When they finally pulled away for air, the smaller pressed a light kiss on his boyfriend’s cheek before nipping at his neck. Grillby hummed appreciatively, jerking off Sans’ spine with a firm grasp. Sans gasped thickly and frappes at Grillby’s shoulders, panting. “m-my spine is sensitive you know?” His words were breathy but still got the message across enough for the taller not to stop.

“hah, fuck… y-you have no clue how good that feels…” His spine gave pleasure, definitely, but a more calm type, hazy eyes and breathy moans. “w-wait…” Grillby stopped, albeit reluctantly, letting his lover speak. “t-the whole reason i wanted t-to do this was so I could s-show you I’m loyal…” The taller opened his mouth to shush him, but Sans cut Grillby off by quickly kissing him. “blindfold me. tie me up, whatever you want. whatever will show you I trust you.”

Grillby’s heart melted, of course, he knew Sans was loyal and he knew Sans trusted him, but the fact of his lover not being able to move or see was too good to pass up. “I do trust you, Sans, I know you’re loyal, Love. But… if it would ease your mind…” Grillby gave him a suggestive look, slipping a hand down to the smaller’s tailbone and giving it a long and tight squeeze. Sans gripped his shirt tighter, his tongue lolling out, and eyes quickly going hazy at the sheer intensity of it.

“oh fuck, please…”

Grillby gave in to his words, keeping one hand one his tailbone while the other cupped the smaller’s cheek. The fire monster gently caressed the old burn mark, he still felt terrible about hurting him even after Sans told him many times that, it didn’t hurt anymore. “I’m so sorry, Love…” Sans looked confused at first, then noticed the hand. He fought through the pleasure and his tailbones throbbing to place a hand on top of the taller’s. 

“you di-didn’t mean to… I know you would never mean to hurt me…” Grillby sighed, “That’s true, but… Sans, Love, if there would have been a lick of intent I could’ve... No, I would’ve killed you… I couldn’t live with myself if I…” Sans shushed him with a kiss that muffled the loud moan he let out when Grillby squeezed tighter. “I- I trust you with my life. hell, you saved it tonight! I- i love and trust you with all my soul.” The fire monster froze, Sans biting back a scream as he gripped his tailbone as tight as he could. The smaller trembled, tears quickly pecking at his eyes. 

The reason, because what Sans said, in monster terms was basically a proposal. 

And it was the Hottest, Cutest, and Most Innocent thing he’d ever heard.

Grillby quickly took off his dress shirt with one hand, before using both to type Sans’ hands behind his back. The chucked his tank top under it onto the smaller’s face, creating a make-shift blindfold by tying it in the back. Sans felt around with his face until he found the crook of Grillby’s neck, snuggling into it. The fire monster breathed deeply to control himself from fucking his lover into the ground. He set the smaller further seated in his lap, “Sans… Do… Do you have any clue of what you just said?” The skeleton tilted his head up as if to look at him, even if he couldn’t.

“n-no? It wasn’t anything bad right? I grew up a lab rat, I don’t know..?” Grillby was blushing furiously, eyes hazy with the confession trowing his arousal into high gear. “Nothing bad no… You just… you basically just proposed to me,” Sans choked on air, struggling in his bindings. “s-shit! I- I’m sorry, I d-didn’t know-” Grillby cut him off with a kiss and when he pulled away both were left panting, but for completely different reasons. Sans, for air, Grillby… because his lover’s words legitimately started his heat cycle.

The taller quickly undressed both of them and positioned himself at Sans’ entrance. “Do. You. Have. Any. Clue. How. Hot. That. Was!?” He punctured every word with a harsh thrust, hilting instantly. Sans cried out, wrapping his legs around Grillby, which only angled his member directly into his G-Spot. He gasped thickly, struggling as much as he could until Grillby eventually slammed against his cervix and the smaller screamed. 

“aHHAh! fUCK GrillbY PLEASE!!”

Grillby yanked his own shirt from binding Sans’ wrists, letting his lover claw his back at how intense the pleasure was. Soon enough, the smaller froze, gasping, “I’m gonna cum-- oh fOX-- NGaahHAHH! S-so c-clOSE-!” Grillby grabbed the sheets with one hand, using the other to steady his lover. The fire monster came with a yelp, an orgasm so intense hot tears pecked his eyes. He slammed deep inside of Sans, pushing hard against the smaller’s cervix. The skeleton came just as hard, accidentally leaving two big rows of scratches down Grillby’s back.

The fire monster fell back, Sans collapsing on top of him. They laid there, panting for air. Sans shakily tried to undo the blindfold, failing. Grillby, just as shakily, took it off for him. The smaller’s eyes fluttered open, quickly seeing him lover breathing hard and staring him down with nothing but true love and affection. Grillby smiled softly, gently brushing a tear from Sans’ face. The skeleton scooched up on his forearms weakly, before nuzzling into his lover’s neck. Grillby draped an arm over Sans’ back before both fell asleep.

==========================

When they woke up that morning, Sans felt awfully sick. The day proceeded with Grillby letting his employees run the bar and sitting on the bathroom floor next to the toilet, a hand placed comfortably and reassuringly on the smaller’s upper back. Sans had one hand gripping the toilet and the other holding his ecto-stomach. He lurched again, groaning in pain. Grillby felt terrible for him, he already could barely walk after the night before, now he was sick! 

Grillby froze.

“Sans- We didn’t-”

Sans froze as well.

“oh fox- you were in heat and you came in-”

Sans grabbed the hem of his shirt, then hesitated. “Grillby… if- if I am expecting… what… what happens to… us..?” Grillby laid a hand on Sans shoulder, “I’ve always wanted a family, Love. More than anything in the world.” Sans smiled weakly, “me too… and if I’m not?” The fire monster placed his other hand on the skeleton’s waist, “Nothing changes, Sugar skull, nothing at all. If we both want kids in the future, then we should talk about it and try for one.”

Sans smiled and lifted his shirt.

Just a blue ecto stomach, surprisingly skinny compared to what people think of Sans. Even as it had a bit of chub, Grillby found it adorable. But that was it, no little souls trapped there or any of Grillby’s magic. All there was, was just a churning swarm of extra magic around where his stomach would be. Both sighed but hugged anyway. “guess everything’s gonna be okay?” Grillby smiled, “Of course, Love.” They went to kiss but Sans’ magic acted up again, gagging, and the couple went back to the toilet.

Nothing changed after all.


End file.
